Figuring out Fertile days....

N • 36 yrs old, Married to the love of my life! Trying for #3 since July 2015 after 2 losses!
Ok ladies. Maybe Tmi but I'm trying to get my Fertile days down right. So along with the ovulation testing I'm using Glow. My periods have been changing down to 2 days consecutively for the last 2 months. But cramps are miserable! I actually noticed light spotting after wiping yesterday & today. Would you ladies consider that part of your period or not? My periods are finally consistent since I started prenatals! What would you ladies say?? TIA! :)